The goal of this project is continue development of a computerized self-management program to encourage and promote exercise, especially for sedentary individuals, based on accepted standards of exercise prescription and behavioral adherence, and to evaluate this program in a randomized controlled trial. In Phase I, a prototype program was developed and was tested with 52 sedentary adults. The aims of Phase I were met or exceeded, and the results of the initial feasibility trial were positive with increased caloric expenditure and improved cardiovascular fitness and flexibility. For Phase II, the prototype FitnessPC program will be further improved based on the results of Phase I and developed in a PDA with web syncing environment to best utilize recent technological advances to offer a full range of exercise adherence interventions. Upon completion of this re-development effort, the program will be tested in an initial pilot trial, and then evaluated in a randomized controlled trial of 200 sedentary individuals comparing the FitnessPC program to a self-help exercise manual. Subjects will be evaluated at weeks 0, 6, 12 and 26 on a variety of anthropometric, physical activity, and physical fitness measures. Results from this trial will be utilized for development of an empirically based commercial exercise adherence program and will provide additional data on the efficacy of computer-mediated interventions for exercise. PROPOSED COMMERCIAL APPLICATION: The primary market for this project are the approximately 8596 of U.S. adults who do not presently meet the minimal recommendations for physical activity. Although other computerized exercise programs have recently become available, the proposed product provides a comprehensive behavioral exercise adherence and prescription program which is empirically and theoretically based, as targets primarily sedentary individuals, not regular exercisers.